I can't find the solution to
In this project I can't use Display Suite. I also can't find a template suggestion for a field group?
How do I manage to do this?
A solution would be to install the Display Suite module.
Once both Display Suite and Display Suite UI modules are enabled you must go to the presentation, choose a layout at the bottom and save, then you will have a lot of fields that weren't available before. One of those fields is the node title.